Threading device for calender rollers



Jan. 8, 1957 H. w. MCAFoos THREADING DEVICE FOR CALENDER ROLLERS Filed Feb. 29, 1952 FIC-LI.

FIGB

United States Patent O THREADING DEVICE FOR CALENDER ROLLERS Herbert Ward McAfoos, Alton, Ill. Application February 29, 1952, Serial No. 274,125

2 Claims. (Cl. 92-74) This invention relates to paper calendering machines and is more particularly directed to an improved device for threading a web of paper into a stack of calender rollers.

The primary object of the invention is to produce a web threading device for a stack of rollers which will rapidly and accurately thread the web through the stack.

Another object of the invention is to produce a threading device'which is readily adjustable for various size rollers.

A further object of the invention is to provide mechanism in a web threading device which permits it to be swung or moved clear of the stack when encountering lumps or high spots in the web.

The invention consists in the provision of a frame for rotatably supporting a plurality of rollers, the frame including pivoted sections at each end thereof and resiliently urged toward the roller, one of the sections pivotally supporting a doctor plate which is resiliently urged against the preceding roller.

The invention further consists in the provision of a frame for a web threading device rotatably supporting a plurality of rollers, the frame being divided into a number of pivoted sections spring-pressed toward the cooperating roller of the calender stack, one of said sections pivotally supporting means for guiding the web of paper into the threading device.

In the drawings:

Fig. 1 is a side elevational view of a device embodying the invention,

Fig. 2 is a rear elevational view thereof; and

Fig. 3 is a sectional view taken substantially along the line 3 3 of Fig. 2.

The invention is disclosed in the several views of the drawings in which the numeral 1 designates a bracket securable to a suitable spacer mounted on the bearing housing (neither of which is shown) for one of the rollers 2 of a calender stack for paper mills. The reason for so mounting the bracket is that it will move with the roller whenever it is forced to move vertically by reason of imperfections, lumps or other variation in the thickness of the paper web passing through the calender stack.

The threading device 3 is pivotally supported on bracket 1 through a lluid motor 4, the connection between the lluid motor and the bracket comprising a pair of arms 5, one end of each being secured to the iluid motor 4, the other end of each arm located at opposite ends of a bearing 6 integral with the bracket 1. A pin 7 extends through apertures in arms and through the bearing 6. A spring 9 and a detent ball 8 are assembled in a socket 10 cut in bearing 6. The ball engages a socket in plug 11 threaded into one of the arms 5. The detent permits the threading device 3 to be swung away from its cooperating roller whenever an imperfection or thickened part of the paper web lodges between the device and the roller. The detent is made sufciently strong to hold the threading device opposite the roller during normal operation thereof.

rice

The threading device 3 comprises a curved frame 12 secured to the piston rod 13 of iiuid motor 4. The uid motor moves the threading device toward the roller 2 and a spring 14 withdraws it from roller 2. In this particular disclosure the spring 14 is located between piston 15 and the end of the iluid motor, which motor is connected to a suitable source of pressure fluid for moving the threading device toward roller 2. A pair of rollersf16 are rotatably mounted in the frame 12. Auxiliary frame members 17 are pivoted to curved frame member 12 and rollers 1S are rotatably supported in the auxiliary frame members. These members are urged toward the calender rollers 2 by means of springs 19 whose tension is adjusted by means of screws 20. The purpose of these auxiliary frame members is to afford rapid adjustment of the threading device when used on rollers of different size, thereby obviating the necessity of providing a separate threading device for calender stack rollers of different diameter.

The threading device to be used as a starter threader, shown on the upper part of Fig. 1, has an adjustable feedv lip 21 pivotally supported on the outer end of the auxiliary frame member 17. This lip is adjusted by means of a screw 22. The function of the feed lip is to permit the operator to quickly start a web of paper between the threading device and the upper roller 2.l The operator forms what is known as a tail on the web of paper and places it between the lip and the upper roller so that the threading device will start it on the way through the calender stack. The threading devices for all the other rollers are provided with a doctor plate 23 pivotally secured to the upper auxiliary member 17. These doctor plates are preferably pivoted on the axes of the rollers 18 and provided with springs 24 Whose tension is adjusted by means of a screw 25 for urging the edge 26 of the doctor plate into engagement with the preceding roller 2. Any tendency of the paper stock toV adhere to the preceding roller is prevented by means of the doctor plate and should there be a momentary separation of the rollers by reason of irregularities in the paper, the springs 24 will cause the doctor plate to follow the movement of the roller, thus causing the paper stock to pass between the threader and the cooperating succeeding roller.

The doctor plate 23 of the succeeding rollers subtends a larger chord than the doctor plate of the rst stripper threader. The reason for this is that the span between the point of contact of the rollers and the succeeding stripper threader is greater than the same space on the first mentioned stripper threader.

The threading device of the first threader, known as a starter and those of the lower rollers, known as nip threaders, are constructed in the same manner except for the doctor plate or feed lip as described above.

What I claim is:

1. A device for threading a web through a stack of calender rollers comprising a bracket supportable by one of the bearing housings of the roller with which the device cooperates, a uid motor including a piston and piston rod, arms associated with said motor, a pin for pivoting said arms to said bracket, a frame secured to said piston rod, rollers rotatably mounted in said frame for engagement with the cooperating roller, a frame section pivoted to each end of said frame resiliently urged toward the cooperating roller, a roller rotatably mounted in each frame section, a doctor plate pivotally mounted in one of said frame sections resiliently urged into engagement with the cooperating roller, spring means for moving said frame away from the cooperating roller after said fluid motor has moved the frame toward the cooperating roller; and detent means operable between said bracket and arms for permitting said trame to be 3 swung away from the cooperating roller when a thickened portion in the web passes between the device and the cooperating roller.

2. A device for threading a web through a stack of calender rollers comprising a bracket supportable by one of the bearing housings of the roller with which the device cooperates, a uid motor including a piston and piston rod, arms associated with said motor, a pin for pivoting said arms to said bracket, a frame secured to said piston rod, rollers rotatably mounted in said frame for engagement with the cooperating roller, a rame section pivoted to each end of said frame, a roller rotatably mounted in each frame section, resilient means for urging each frame section toward the cooperating roller, detent means for permitting said frame to rnove away from the cooperating roller when imperfections in the web pass between the frame roller and the calender rollers; and an adjustable lip pivotally mounted on one of said frame sections for assisting in feeding the web into the device.

References Cited in the rile of this patent UNITED STATES PATENTS 896,736 Mason Aug. 25, 1908 945,479 Smith Jan. 4, 1910 1,598,793 Ward Sept. 7, 1926 2,013,942 Albright Sept. 10, 1935 2,022,009 Rocca Nov. 26, 1935 2,404,946 Clem July 30, 1946 2,635,872 Birse Apr. 21, 1953 2,651,242 Neely Sept. 8, 1953 FOREIGN PATENTS 198 Great Britain Jan. 15, 1878 13,436 Germany Mar. 31, 1880 OTHER REFERENCES Paper Feed Mechanism for Calender Rolls, The Paper lndustry and Paper World, January 1948; page 1518. f 

